The present invention relates to a projection type television receiver, and a method of manufacturing the same, and more particularly to its cabinet structure.
A conventional projection type television receiver has a wooden cabinet of one-body structure. A cathode-ray tube (CRT), an optical unit, a reflection mirror, a control circuit board (also known as chassis or printed wiring board), a speaker system, and others are disposed in the wooden cabinet. A screen frame, a transmission type screen, a speaker grill, a back cover and others are provided at the outer side of the wooden cabinet. The transmission type screen includes a Fresnel lens sheet and a lenticular lens sheet. In the conventional projection type television receiver, in every different inch size or type of the projection screen, it was necessary to modify the cabinet main body and peripheral parts.
FIG. 18 is a perspective outline view of a conventional projection type television receiver. In FIG. 18, a transmission type screen 53, a screen frame 49, a speaker grill 50, a back cover 51, and others are provided in a one-body wooden cabinet 48. Speakers 52 are also provided in the wooden cabinet 48.
However, the conventional one-body type wooden cabinet had the following problems. It was difficult to reduce in size and weight. When changing over models, it was necessary to make new parts such as cabinet and other components, and it was hard to use the parts commonly. When changing the speaker unit, too, it was necessary to modify the cabinet main body. Further, it required many steps in manufacturing the apparatus.
A projection type television receiver of the invention comprises:
(a) a chassis,
in which the chassis includes a lower cabinet, a lower cover fitted to the lower cabinet, an image display device, a speaker system, an optical unit, and a control circuit, and
(b) a projection unit installed at the upper side of the chassis, in
which the projection unit includes an upper cabinet, an upper back cover fitted to the upper cabinet, a transmission type screen, and a reflection mirror,
in which the chassis and the projection unit are mutually linked.
In this configuration, corresponding to the projection unit of various sizes, one large chassis can be used. That is, in the projection type television receivers having the projection units of various sizes, one chassis can be commonly used. As a result, the cost can be reduced.
A manufacturing method of projection type television receiver of the invention comprises:
(a) a step of making a lower cabinet,
(b) a step of making a lower back cover,
(c) a step of making an upper cabinet,
(d) a step of making an upper back cover,
(e) a step of fitting the lower back cover to the lower cabinet, and
(f) a step of coupling the upper back cover and upper cabinet on the lower cabinet by coupling means.
In this configuration, one chassis can be commonly used in the projection type television receivers having projection units of various sizes. Moreover, the assembling work is easy. Hence, the cost can be reduced.
Preferably, the lower cabinet has a speaker box, and the speaker box is integrally formed in the lower cabinet. As a result, the rigidity of the lower cabinet is enhanced.
Preferably, the speaker box is formed integrally in the lower cabinet, at both corners of the top side of the lower cabinet, and the speaker box has a plurality of ribs formed on the top of the speaker box. As a result, vibration generated in the speaker box is prevented from propagating to the projection unit.
Preferably, the lower cabinet includes a left supplementary side wall installed detachably at the left side of the lower cabinet, and a right supplementary side wall installed detachably at the right side of the lower cabinet. As a result, corresponding to the change of lateral width dimension of the upper cabinet, the size of the lower cabinet can be changed.
Preferably, the projection type television receiver further comprises at least one selected from the group consisting of a first plumb placed in the bottom of the lower cabinet, a first plumb placed in the rear part of the upper back cover, and an anti-tumble leg placed in the front lower part of the lower cabinet. As a result, tumbling of the projection type television receiver is prevented.
Preferably, the lower cabinet has a partition wall placed in the lower cabinet, and the cabinet has a plurality of spaces divided by the partition wall. The chassis has a plurality of control circuit boards, and each one of the plurality of control circuit boards is placed at least in two spaces of the plurality of spaces. As a result, mutual thermal effects of the control circuit boards is prevented.
Preferably, the projection type television receiver has a plate placed between the chassis and the projection unit so as to divide into the chassis and the projection unit. As a result, invasion of at least dust and heat is prevented mutually in the chassis and projection unit.